AI-generated Key Takeaways
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A Treemap is a visual representation of hierarchical data where nodes are displayed as rectangles sized and colored according to assigned values.
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Nodes in a Treemap are displayed as rectangles, sized and colored relative to other nodes in the graph.
-
User interaction with a Treemap defaults to moving down the tree on a left-click and moving back up on a right-click.
-
Treemap tooltips can be customized by defining a JavaScript function and setting the
generateTooltipoption. -
The Treemap visualization requires a data table with four columns: node ID, parent ID, size, and an optional color value.
Overview
A visual representation of a data tree, where each node can have zero or more children, and one parent (except for the root, which has no parents). Each node is displayed as a rectangle, sized and colored according to values that you assign. Sizes and colors are valued relative to all other nodes in the graph. You can specify how many levels to display simultaneously, and optionally to display deeper levels in a hinted fashion. If a node is a leaf node, you can specify a size and color; if it is not a leaf, it will be displayed as a bounding box for leaf nodes. The default behavior is to move down the tree when a user left-clicks a node, and to move back up the tree when a user right-clicks the graph.
The total size of the graph is determined by the size of the containing element that you insert in your page. If you have leaf nodes with names too long to show, the name will be truncated with an ellipsis (...).
Example
<html>
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load('current', {'packages':['treemap']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable([
['Location', 'Parent', 'Market trade volume (size)', 'Market increase/decrease (color)'],
['Global', null, 0, 0],
['America', 'Global', 0, 0],
['Europe', 'Global', 0, 0],
['Asia', 'Global', 0, 0],
['Australia', 'Global', 0, 0],
['Africa', 'Global', 0, 0],
['Brazil', 'America', 11, 10],
['USA', 'America', 52, 31],
['Mexico', 'America', 24, 12],
['Canada', 'America', 16, -23],
['France', 'Europe', 42, -11],
['Germany', 'Europe', 31, -2],
['Sweden', 'Europe', 22, -13],
['Italy', 'Europe', 17, 4],
['UK', 'Europe', 21, -5],
['China', 'Asia', 36, 4],
['Japan', 'Asia', 20, -12],
['India', 'Asia', 40, 63],
['Laos', 'Asia', 4, 34],
['Mongolia', 'Asia', 1, -5],
['Israel', 'Asia', 12, 24],
['Iran', 'Asia', 18, 13],
['Pakistan', 'Asia', 11, -52],
['Egypt', 'Africa', 21, 0],
['S. Africa', 'Africa', 30, 43],
['Sudan', 'Africa', 12, 2],
['Congo', 'Africa', 10, 12],
['Zaire', 'Africa', 8, 10]
]);
tree = new google.visualization.TreeMap(document.getElementById('chart_div'));
tree.draw(data, {
minColor: '#f00',
midColor: '#ddd',
maxColor: '#0d0',
headerHeight: 15,
fontColor: 'black',
showScale: true
});
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>
Highlights
You can specify whether elements should highlight, and set specific colors for
certain elements to use when this occurs. To turn on highlighting, set highlightOnMouseOver:true
(for v49 or before) or enableHighlight: true
(for v50+).
From there, you can set your colors to use
for highlighting elements using the various HighlightColor
options.
var options = { // For v49 or before highlightOnMouseOver : true , maxDepth : 1 , maxPostDepth : 2 , minHighlightColor : '#8c6bb1' , midHighlightColor : '#9ebcda' , maxHighlightColor : '#edf8fb' , minColor : '#009688' , midColor : '#f7f7f7' , maxColor : '#ee8100' , headerHeight : 15 , showScale : true , height : 500 , useWeightedAverageForAggregation : true }; var optionsV50 = { // For v50+ enableHighlight : true , maxDepth : 1 , maxPostDepth : 2 , minHighlightColor : '#8c6bb1' , midHighlightColor : '#9ebcda' , maxHighlightColor : '#edf8fb' , minColor : '#009688' , midColor : '#f7f7f7' , maxColor : '#ee8100' , headerHeight : 15 , showScale : true , height : 500 , useWeightedAverageForAggregation : true , // Use click to highlight and double-click to drill down. eventsConfig : { highlight : [ 'click' ], unhighlight : [ 'mouseout' ], rollup : [ 'contextmenu' ], drilldown : [ 'dblclick' ], } };
Tooltips
By default, treemap tooltips are basic, showing the label of the treemap cell. This is useful when the cells are too small to contain the labels, but you can customize them further as described in this section.
Treemap tooltips are customized differently than other charts: you
define a function and then set the generateTooltip
option
to that function. Here's a simple example:
In the above chart, we define a function called showStaticTooltip
that simply returns a string with the HTML to be shown whenever the user hovers over a treemap cell. Try it! The code to generate that is as follows:
var options = { minColor: '#e7711c', midColor: '#fff', maxColor: '#4374e0', showScale: true, generateTooltip: showStaticTooltip }; tree.draw(data, options); function showStaticTooltip(row, size, value) { return '<div style="background:#fd9; padding:10px; border-style:solid">' + 'Read more about the <a href="http://en.wikipedia.org/wiki/Kingdom_(biology)">kingdoms of life</a>.</div>'; }
The generateTooltip
function can be any JavaScript you
like. Usually, you'll want tooltips that vary based on the data
values. The following example shows how to access every field in the
datatable.
If you hover over the cells in the above treemap, you'll see a
different tooltip for each cell. The treemap tooltip functions all
take three values: row
, size
,
and value
.
-
row: the cell's row from the datatable -
size: the sum of the value (column 3) of this cell and all its children -
value: the color of the cell, expressed as a number from 0 to 1
In showFullTooltip
, the string we return is an HTML
box with five lines:
- Line 1 shows the appropriate row from the datatable, making
liberal use of
data.getValue. - Line 2 tells you which row that is, which is just
the
rowparameter. - Line 3 gives you information from column 3 of the datatable: the sum of the value of column 3 from this row, plus the values from descendants.
- Line 4 gives you information from column 4 of the datatable. It's the value, but expressed as a number between 0 and 1 corresponding to the color of the cell.
var options = { minColor: '#e7711c', midColor: '#fff', maxColor: '#4374e0', showScale: true, generateTooltip: showFullTooltip }; tree.draw(data, options); function showFullTooltip(row, size, value) { return '<div style="background:#fd9; padding:10px; border-style:solid">' + '<span style="font-family:Courier"><b>' + data.getValue(row, 0) + '</b>, ' + data.getValue(row, 1) + ', ' + data.getValue(row, 2) + ', ' + data.getValue(row, 3) + '</span><br>' + 'Datatable row: ' + row + '<br>' + data.getColumnLabel(2) + ' (total value of this cell and its children): ' + size + '<br>' + data.getColumnLabel(3) + ': ' + value + ' </div>'; } }
Loading
The google.charts.load
package name is "treemap"
.
google . charts . load ( "current" , { packages : [ "treemap" ]});
The visualization's class name is google.visualization.TreeMap
.
var visualization = new google . visualization . TreeMap ( container );
Data Format
Each row in the data table describes one node (a rectangle in the graph). Each node (except the root node) has one parent node. Each node is sized and colored according to its values relative to the other nodes currently shown.
The data table should have four columns in the following format:
- Column 0 - [ string ] An ID for this node. It can be any valid JavaScript string, including spaces, and any length that a string can hold. This value is displayed as the node header.
- Column 1 - [ string ] - The ID of the parent node. If this is a root node, leave this blank. Only one root is allowed per treemap.
- Column 2 - [ number ] - The size of the node. Any positive value is allowed. This value determines the size of the node, computed relative to all other nodes currently shown. For non-leaf nodes, this value is ignored and calculated from the size of all its children.
- Column 3 - [ optional
, number
] - An optional value used to
calculate a color for this node. Any value, positive or negative, is allowed.
The color value is first recomputed on a scale from
minColorValuetomaxColorValue, and then the node is assigned a color from the gradient betweenminColorandmaxColor.
Configuration Options
Determines if elements should show highlighted effects. The default trigger is when moused over.
The trigger can be configured with eventsConfig
. If set to true
, highlighting for different elements can be specified using the various highlightColor
options.
The event configuration to trigger tree map interactions. Format to configure interactions:
eventsConfig : { interaction1 : undefined , // or missing interaction2 : [], // disable interaction3 : [ 'mouse_event' , 'optional_key1' , 'optional_key2' , 'optional_key3' , 'optional_key4' ], ..., }
mouse_event
is required and must be a supported mouse event. Then you can have up to four optional key modifiers.- Supported interactions:
- highlight, unhighlight, rollup, drilldown .
- Supported mouse events:
- 'click', 'contextmenu', 'dblclick', 'mouseout', 'mouseover' . With 'contextmenu' corresponds to the right-click.
- Supported mouse event modifier keys:
- 'altKey', 'ctrlKey', 'metaKey', 'shiftKey' .
- Get the current configuration:
- Call method
getEventsConfig().
{ rollup : [ 'contextmenu' , 'ctrlKey' , 'shiftKey' ] }
{ highlight : [ 'mouseover' ], unhighlight : [ 'mouseout' ], rollup : [ 'contextmenu' ], // right-click drilldown : [ 'click' ] }
The text color. Specify an HTML color value.
The font family to use for all text.
The font size for all text, in points.
Draws the chart inside an inline frame. (Note that on IE8, this option is ignored; all IE8 charts are drawn in i-frames.)
The color of the header section for each node. Specify an HTML color value.
The height of the header section for each node, in pixels (can be zero).
The color of the header of a node being hovered over. Specify an HTML color value or null;
if null this value will be headerColor
lightened by 35%.
Deprecated for v50+. For v50 and later, please use enableHighlight
.
Determines if elements should show highlighted effects when moused over. If set to true
, highlighting for different elements can be specified using the various highlightColor
options.
When maxPostDepth
is greater than 1, causing nodes below the current depth to
be shown, hintOpacity
specifies how transparent it should be. It should be
between 0 and 1; the higher the value, the fainter the node.
The color for a rectangle with a column 3 value of maxColorValue
. Specify an
HTML color value.
The maximum number of node levels to show in the current view. Levels will be flattened
into the current plane. If your tree has more levels than this, you will have to go up or
down to see them. You can additionally see maxPostDepth
levels below this as
shaded rectangles within these nodes.
The highlight color to use for the node with the largest value in column 3. Specify an HTML
color value or null; If null, this value will be the value of maxColor
lightened by 35%
How many levels of nodes beyond maxDepth
to show in "hinted" fashion.
Hinted nodes are shown as shaded rectangles within a node that is within the maxDepth
limit.
The maximum value allowed in column 3. All values greater than this will be trimmed to this value. If set to null, it will be set to the max value in the column.
The color for a rectangle with a column 3 value midway between maxColorValue
and minColorValue
. Specify an HTML color value.
The highlight color to use for the node with a column 3 value near the median of minColorValue
and maxColorValue
. Specify an HTML color value or
null; if null, this value will be the value of midColor
lightened by 35%.
The color for a rectangle with the column 3 value of minColorValue
. Specify an
HTML color value.
The highlight color to use for the node with a column 3 value nearest to minColorValue
. Specify an HTML color value or null; if null, this value will
be the value of minColor
lightened by 35%
The minimum value allowed in column 3. All values less than this will be trimmed to this value. If set to null, it will be calculated as the minimum value in the column.
The color to use for a rectangle when a node has no value for column 3, and that node is a leaf (or contains only leaves). Specify an HTML color value.
The color to use for a rectangle of "no" color when highlighted. Specify an HTML
color value or null; if null, this will be the value of noColor
lightened by
35%.
Whether or not to show a color gradient scale from minColor
to maxColor
along the top of the chart. Specify true to show the scale.
Whether to show tooltips.
An object that specifies the text style, for certain charts that have text in the content area such as the treemap. The object has this format:
{ color: <string>,
fontName: <string>,
fontSize: <number>,
bold: <boolean>,
italic: <boolean> }
The color
can be any HTML color string, for example: 'red'
or '#00cc00'
. Also see fontName
and fontSize
.
{color: 'black', fontName: <global-font-name>, fontSize: <global-font-size>}
Text to display above the chart.
An object that specifies the title text style. The object has this format:
{ color: <string>,
fontName: <string>,
fontSize: <number>,
bold: <boolean>,
italic: <boolean> }
The color
can be any HTML color string, for example: 'red'
or '#00cc00'
. Also see fontName
and fontSize
.
{color: 'black', fontName: <global-font-name>, fontSize: <global-font-size>}
Whether to use weighted averages for aggregation.
Methods
draw(data, options)
Draws the chart.
getEventsConfig() (for v50+)
Returns the current interaction configuration. This can be used to verify the configuration option eventsConfig
{ // An empty array (i.e. []) means the interaction is disabled. highlight : string [], unhighlight : string [], rollup : string [], drilldown : string [] }
getSelection()
Standard getSelection()
implementation. Selected elements are nodes. Only one node can be selected at a time.
setSelection()
Standard setSelection()
implementation. Selected elements are nodes. Only one node can be selected at a time.
goUpAndDraw()
Move up the tree by one level and redraw it. Does not throw an error if the node is the root node. This is fired automatically when the user right-clicks a node.
getMaxPossibleDepth()
Returns the maximum possible depth for the current view.
clearChart()
Clears the chart, and releases all of its allocated resources.
Events
onmouseover
Fired when the user mouses over a node. The event handler is passed the row index of the corresponding entry in the data table.
highlight (for v50+)
Fired when the user highlights a node. The default trigger is mouseover.
It can be configured with eventsConfig
for v50+.
The event handler is passed the row index of the corresponding entry in the data table.
onmouseout
Fired when the user mouses out of a node. The event handler is passed the row index of the corresponding entry in the data table.
unhighlight (for v50+)
Fired when the user unhighlights a node. The default trigger is mouseout.
It can be configured with eventsConfig
for v50+.
The event handler is passed the row index of the corresponding entry in the data table.
ready
Fired when chart is ready for external method calls. If you want to interact with the chart,
and call methods after you draw it, you should set up a listener for this event before
you call the draw
method, and call them only after the event was
fired.
rollup
Fired when the user navigates back up the tree. The default trigger is right-clicking.
It can be configured with eventsConfig
for v50+.
The row property passed into the event handler is the row of the node that the user is navigating from
, not the row the user is navigating to
.
select
Fired when the user drills down, or rolls up a node. Also fired when method setSelection()
or goUpAndDraw()
is called.
To learn which node was selected, call getSelection()
.
drilldown (for v50+)
Fired when the user navigates deeper into the tree. The default trigger is clicking.
It can be configured with eventsConfig
for v50+.
To learn which node was clicked, call getSelection()
.
Data Policy
All code and data are processed and rendered in the browser. No data is sent to any server.
